Insulating panel



April s, 1954 2,674,015

S. E. MAUTNER vINSULATING PANEL Filed Sept. 8, 1947 iO ii i5 Q4 Q7 By INVEN TOR.

ATTORNEYS.

Patented Apr. 6, 1954 IN SULATING .PANEL Steven E. Mautner, Port Jervis,N. Y., assignor to Skydyne, Inc.Port Jervis, N.;Y., a corporation of NewYork Application September 8, 1947,l Serial No. 772,730

4 Claims. (Cl. 20-4) My invention relates to insulating panels and inparticular to a panel having lire-resistant properties.

It is an object of the invention to provide an improved panelconstruction of the character indicated.

It is another object to provide a light weight rire-resistant panel.v

It is a further object to provide an insulating panel suitable forrepartitlons, bulkheads, or to insilateand to cover aircraft fuselagesand other par s.

It is a still further object to provide an insulating panel'that isrelatively simple to install.

It-is'a general objectof'the invention to provide a panel meeting theabove objects and at the same time one that is relatively inexpensiveand easy to manufacture.

Other objects and various further features of the invention will bepointed out or will occur to those skilled in the art from a reading ofthe following specification in conjunction with the accompanyingdrawings. In said drawings:

Fig.` 1 is, an enlarged, slightly exaggerated, fragmentary sectionalview of a panel construction according to the invention;A

Fig; 2 is a fragmentary' partly broken-away plan view4 of amodiedinsulating. panel according lto thezinvention;

Fig.rr 3 is a sectionalview taken substantiallyv in therplane. 3.--3 ofFig. 2;

Figl. is apartly broken-away plan view of a further modication accordingto the invention; and

Fig..5l is a sectionalview takeny on the plane f Briefly stated, myinvention contemplates an insulating-panel construction utilizing a coreof extremely light material, bounded on opposite sides by protectivelayers of relatively thin metal sheathing. The core and the sheathingmay be substantially coextensive and may be bonded to gether, or theentire assembly may be bound and held in unit-handling relation by aframe of relatively thin metal construction. In a preferred form to bedescribed, a flame-resistant material such as asbestos is interposedbetween the body of the core and the sheathing. If desired, salts havingcombined Water or water of crystallization may be incorporated with thecore.

Referring to Fig. 1 of the drawings, my invention is shown inapplication to a panel having 'I'hecoreV I0 is protected on oppositefaces thereof byrelativelyv thinv metal sheathing, such assteel platesII-I2, which are shown substantially coextensive with the core I0.Channels Iii-I4, which may be of relativelyv thin metal, embrace thesheath plates |I-I2 and the core I0, to

secure the sandwich construction and to render the same unit-handling.The channels I3-I4 may cooperate with other longitudinally extendingchannels (not shown) to complete the framework for a panel of desiredsize, as will be clear.

In accordance with the invention, a flameresistant material may beinterposed between the body of the core I0 and the metal sheathingplates i I-IE.' In the formshown in Fig; 1, this material is asbestoswhich may be applied in the form of a rst relatively thin blanket orlayer I5 between the core I0 and the plate II, and in the form of asecond relatively thin blanket 01 layer I6 between the core I0 and theplate I2.

In Figs. 2 and 3, I illustrate an alternative construction, which may beframed similarly to the frame of Fig. l, but which is perhaps moreadaptable to the employment of flame-resistant materials, such ascrystalline salts that are not readily applied in layers. Thus, in Fig.2, the panel may include a covering sheath I8 of relatively thin metaland a core I9 again preferably of a low-v density cellulose material,such as cellulose or cellular cellulose acetate. The core I9 may includea plurality of openings to retain the salt, and these openings=may beholes 20 drilled (in the form shown part way) through the corev I9, sothat at least ,theopenings-arerexposed to one face of the core I9. Thesalt to be'applied in the openings 20 may be sodium carbonate, an alum,or other salt preferably having substantial water of crystallization,and the salt ll 2| in each opening is preferably leveled off ush withthe surface of the core I9. The salt may thus be said to be interposedbetween the sheath IB and the body of the core I9. The openings in Figs.2 Y

n and 3 may be drilled into the core I9 as suggested a relatively thickcentral core I Il of extremely light or low-density material, such ascellulose (e. g. balsa wood) or cellular cellulose acetate.

above, but in a preferred cellular celluloseacetate construction thepress which forms the core includes a plurality of projections or studswhich may suitably form the openings 2li in the pressing operation.

In the alternative arrangement of Figs, 4 and 5, the panel may againcomprise a core 22 of a cellulose material, such as balsa wood, boundedon opposite sides by sheathing plates such as the plates 23-24- Theflame-resisting salt in the form shown is contained within substantiallyparallel grooves or slots 25, which may be formed 3 opening to one face,say, the upper face, of the panel. Again, the salt lls 2G in thesegrooves or slots 25 are preferably leveled ofi` flush with a surface ofthe core 22. If desired, the opposite surface of the core 22 may beprotected in a similar manner by fills 2l of salt in grooves 28, runningsubstantially parallel to each other and at right angles to the grooves22 on the rst or upper face of the panel core 22.

In application of the above panels to aircraft, it has been founddesirable to make the cellulose or cellulose acetate cores relativelythick, say, of the order of one-quarter to one-half inch thick. Themetal sheathing is preferably of high melting-point material, such assteel, and is of the thinnest tolerable gauge. Twenty-six gauge materialor even thinner will be found to be quite satisfactory. A gauge ofcomparable thickness may be employed in the channel or otherconstruction for framing the panel. In tests oi'riny sandwichconstruction panels, it has been found that up to temperatures of about390 F., the panel materials remain substantially inert. There may beseme steam and gases liberated, and as the temperature is increased theorganic material will char but will retain much of its rire-resistantand insulating properties. The panels have been subjected totemperatures of 2200 F. at one side for periods up to thirty minutes.and the temperature at the other side did not exceed 800 F. Since thesandwich construction is suihciently tight so as to prevent aircirculation, the organic matter does not burn but merely chars andretains much of its insulating properties. struction is reasonablytight, the iori'nation of gas or vapor due to heat may spread the metalsheath plates and even the inner layers and thus form layers of air toact as further insulation or heat transfer retarders.

-In general, the sandwich construction is designed as a iire retarder orheat insulation and after once being subjected to high temperatures, sayof the order of 2000u 1I, would ordinarily be replaced by a new panel orpanels. The panels may be repeatedly heated to moderate temperatures (ofthe order of 390) without substantial loss of eiilciency, but if onceheated to the higher temperatures noted above, the panels would notretain their original emciency on subsequent beatings.

It will be appreciated that I have disclosed a relatively simple panelconstruction which may be ap'plied'with effectiveness to aircraft, andfor other applications, The relatively low density of the more bulkyelement (the fibrous cellulose or ince my sandwich concellulose acetate,at about iive pounds per cubic foot) may assure an extremelylight-weight assembly. The fact that the panel can be formed with theprotective materials in a unit construction makes for easy application,as desired. In certain cases, it may be desirable to utilize my panelconstruction as the sole material for nre partitions, bulkheads, or forthe outer sheet coverage of an aircraft. In such applications the panelmay serve the functions of lire, heat, and noise insulation in additionto performing a structural function.

If desired, the various layers forming the sandwich construction may becemented or bonded together and thus avoid the necessity of the edgeframe I4 shown.

While I have described my invention in detail or the preferred formsshown, it will be understood that further modifications may be madewithin the scope of the invention as defined in the appended claims.

I claim:

1. In a panel of the character indicated, a core of a cellulosematerial, said core having a plurality of openings on one face thereof,a salt having substantial water of crystallization in said openings andleveled off ilush with said face, and a relatively thin metal sheath onopposite sides of said core.

2. A panel according to claim 1, in which said openings are holesextending into said core and are open to one face thereof, and in whichsaid holes are iilled with said salt.

3. A panel according to claim 1, in which said openings aresubstantially. parallel grooves on one face of said core.

4. A panel according to claim 1, in which said openings include a firstplurality of substantially parallel grooves on one face of said core,and a second plurality of substantially parallel grooves on the oppositeface of said core, one plurality of said grooves running generallyperpendicular to the other plurality of said grooves.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 11,842 Sherwood Oct. 24, 1854 128,359 Butler June 25, 1872293,721 Dolman Feb. 19, 1884 513,247 Pritchard Jan. 23, 1894 526,732Norcross Oct. 2, 1894 583,713 Russell June 1, 1897 2,125,286 FletcherAug. 2, 1938 2,377,846 Dreyfus June 5, 1945

1. IN A PANEL OF THE CHARACTER INDICATED, A CORE OF A CELLULOSEMATERIAL, SAID CORE HAVING A PLURALITY OF OPENING ON ONE FACE THEREOF, ASALT HAVING SUBSTANTIAL WATER OF CRYSTALLIZATION IN SAID OPENINGS ANDLEVELED OFF FLUSH WITH SAID FACE, AND A RELATIVELY THIN METAL SHEATH ONOPPOSITE SIDES OF SAID CORE.